Anhedonia Relates to the Altered Global and Local Grey Matter Network Properties in Schizophrenia.

Byung-Hoon Kim,Jung Suk Lee,Hesun Erin Kim,Jae-Jin Kim

doi:10.3390/jcm10071395

Abstract

Anhedonia is one of the major negative symptoms in schizophrenia and defined as the loss of hedonic experience to various stimuli in real life. Although structural magnetic resonance imaging has provided a deeper understanding of anhedonia-related abnormalities in schizophrenia, network analysis of the grey matter focusing on this symptom is lacking. In this study, single-subject grey matter networks were constructed in 123 patients with schizophrenia and 160 healthy controls. The small-world property of the grey matter network and its correlations with the level of physical and social anhedonia were evaluated using graph theory analysis. In the global scale whole-brain analysis, the patients showed reduced small-world property of the grey matter network. The local-scale analysis further revealed reduced small-world property in the default mode network, salience/ventral attention network, and visual network. The regional-level analysis showed an altered relationship between the small-world properties and the social anhedonia scale scores in the cerebellar lobule in patients with schizophrenia. These results indicate that anhedonia in schizophrenia may be related to abnormalities in the grey matter network at both the global whole-brain scale and local–regional scale.

Highlights

Schizophrenia includes diverse symptoms, such as delusions, hallucinations, disorganized speech, disorganized behavior, and negative symptoms [1]
Not much is known about the neurological pathophysiology of negative symptoms, and not many options are available for treating the negative symptoms [6]
The results indicate a possibility that altered grey matter (GM) topology within the reward system may underlie the pathophysiology of social anhedonia via dysfunction of effort computation and reward prediction

Summary

Introduction

Schizophrenia includes diverse symptoms, such as delusions, hallucinations, disorganized speech, disorganized behavior, and negative symptoms [1]. Among these symptoms, negative symptoms are characterized by the absence of certain psychological features, including affective experience, motivation, and verbal or nonverbal expression [2,3]. One of the negative symptoms in schizophrenia is anhedonia, which is defined as the loss of hedonic experience or pleasure to various stimuli in real life [7]. Impairment of the neural networks related to anticipation, emotion processing, salience processing, and attention to the expected or given rewards can all result in the inability to feel pleasure [12,13,14,15]

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